I just completed a 5,000 mile trip and found a problem with the valve stem core on one of the rear tires.

I check tire pressures periodically during the trip and on one occasion, when I removed the cap, I heard air hissing and noticed the core had backed out of the stem. I quickly put the cap back on to stop the leak.

Fortunately I carry a compressor with me and was able to tighten the core and inflate the tire. I went to an auto parts store and bought a core tool that is like a small screwdriver, much easier to use than the one on the end of some tire gages or the multi-purpose core tool that also has thread taps in the shape of a small cross. The tool is also drilled out in the bottom of the slot so that the core does not let air out when tightening.

I checked all stem cores and the ones on the rear dually extenders all needed tightening. I guess the one finally backed out enough to leak when the cap was removed. Fortunately the cap kept the tire from leaking and also limited the amount the stem could back out so that it did not blow out when the cap was removed.

You may want to check the other end of the extenders also. I had one come loose on my other PC and the rear tire was flat before I noticed it. My tire guy told me they gets lots of flat tires from the extenders.

Tagging on to this old thread as others may find it useful...a similar thing happened to me just last week with my '07 2100.

I just had a leaf spring added to my PC (wow, did that make her ride much better!). A day or two later, doing my pre-trip checks, I noticed my inner right rear tire was flat. Took it to the tire shop thinking it had a leak, and they couldn't find anything, put it back together and it held air tight. They checked the extenders/etc but found nothing.

They noted that they do not like the extenders, said they caused a lot of leaks. My theory is when the suspension guys put the wheels back on, one of the extenders leaked.

Another week later, checking the air on my wheels before a trip the other side rear wheels air line extender had a hissing sound after taking my tire gauge off the stem. I monkeyed with the stem best I could but was able to put the cap back on and with the o-ring in it, it held for our weekend outing. Phew.

I agree it's a good post. Extra thanks to all of you. I added the little tool to our Amazon shopping cart. The "Things to keep checking" list keeps getting longer. I know for some of you seasoned RV'ers, it is second nature, but it's pretty mind boggling to us newbies. Note to self - redo the checklists... again.

very good still laughing,,,, I was on a monthly schedule to exercise the genie, roll the tires. now I'm going about every two weeks at least roll the tires, check on things, usually just sit around read a book while the genies running,,, now I have about six things to do and check on... the never ending toils of RV Man,hahah.... yeah it's a pain, a pleasant one because most of the time it's fun,,,, but all that work and little things lead to very enjoyable road trips and not having problems redoing the checklist now and updating the TO DO LIST.. which never ends

Ok 4th time,,, I am still trying to download a pic... purchased this stem valve tool wal mart 1.88. YES it is tied to a lanyard so I do not lose it... I actually have two of these, lost one for three months,,,,, now if I can some how attach a lanyard to the TV remote haha

I just noticed that the tire valve stems on the front tires are not the same type as on the rears. All four rear tires have what I consider to be traditional valve stem cores with caps at the ends. The front tires have no screw-off caps and they have much different looking cores--they look solid out to the tip of the valves.I'm sure someone can explain this to me.

Mine has the 6 and 8 inch valve extensions on the rear, which one should check the tighness on the valve stem as well as the four cores. The front has the half inch valve caps that allow adding air without removing them. One should remove them and check the valve core also. I do this every year, but some say I am anal about stuff like this.

Bruce Like tom said you probably have the non screw valve caps, you should be able to check the air pressure on them,, try it, If I am right they should actually screw off to your regular looking valve stems, I guess you could call them extensions. hehe,,, the tip will have a movable ball/spot in the middle where you can fill or check the pressure. they just make it easier to check or fill. again take your gauge or a key and push down on the middle should give,David sparks2008 PC 2350Houston